scholarly journals Biosilica from Living Diatoms: Investigations on Biocompatibility of Bare and Chemically Modified Thalassiosira weissflogii Silica Shells

2016 ◽  
Vol 3 (4) ◽  
pp. 35 ◽  
Author(s):  
Stefania Cicco ◽  
Danilo Vona ◽  
Roberto Gristina ◽  
Eloisa Sardella ◽  
Roberta Ragni ◽  
...  
Keyword(s):  
Thalassiosira Weissflogii ◽  
Chemically Modified ◽  
Living Diatoms

Light emitting silica nanostructures by surface functionalization of diatom algae shells with a triethoxysilane-functionalized π-conjugated fluorophore

MRS Advances ◽  
2015 ◽  
Vol 1 (57) ◽  
pp. 3817-3823 ◽  
Author(s):  
Danilo Vona ◽  
Marco Lo Presti ◽  
Stefania Roberta Cicco ◽  
Fabio Palumbo ◽  
Roberta Ragni ◽  
...  
Keyword(s):  
Surface Functionalization ◽  
Organic Dye ◽  
Diatom Algae ◽  
Thalassiosira Weissflogii ◽  
Light Emitting ◽  
Biotechnological Approach ◽  
Silica Nanostructures ◽  
Organic Fluorophore ◽  
Living Diatoms

ABSTRACTThe functionalization of biosilica shells (frustules) of diatoms microalgae with a tailored luminescent molecule is a convenient, scalable and biotechnological approach for obtaining new light emitting silica nanostructures with promising applications in photonics. In particular, here we report the synthesis of a red emitting organic fluorophore and its covalent linking to the surface of mesoporous biosilica extracted from Thalassiosira weissflogii diatoms cultured in our laboratories. The organic dye has a conjugated skeleton composed of thienyl, benzothiadiazolyl and phenyl units and a peripheral triethoxysilyl group which enables its stable binding onto the frustules surface. The protocol to extract the biosilica shells from living diatoms preserving their natural ornate nanostructured morphology is also discussed.

Binding of Tissue Plasminogen Activator to Vascular Grafts

1989 ◽  
Vol 61 (01) ◽  
pp. 131-136 ◽  
Author(s):  
Richard A Harvey ◽  
Hugh C Kim ◽  
Jonathan Pincus ◽  
Stanley Z Trooskin ◽  
Josiah N Wilcox ◽  
...  
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Fibrinolytic Activity ◽  
Polymer Surface ◽  
Enzymic Activity ◽  
Vascular Prostheses ◽  
Chemically Modified ◽  
Insoluble Surfactant ◽  
Tissue Plasminogen

SummaryTissue plasminogen activator labeled with radioactive iodine (125I-tPA) was immobilized on vascular prostheses chemically modified with a thin coating of water-insoluble surfactant, tridodecylmethylammonium chloride (TDM AC). Surfactant- treated Dacron, polytetrafluoroethylene (PTFE), silastic, polyethylene and polyurethane bound appreciable amounts of 125I- tPA (5-30 μg 125I-tPA/cm2). Upon exposure to human plasma, the amount of 125I-tPA bound to the surface shows an initial drop during the first hour of incubation, followed by a slower, roughly exponential release with a t½ of appoximately 75 hours. Prostheses containing bound tPA show fibrinolytic activity as measured both by lysis of clots formed in vitro, and by hydrolysis of a synthetic polypeptide substrate. Prior to incubation in plasma, tPA bound to a polymer surface has an enzymic activity similar, if not identical to that of the native enzyme in buffered solution. However, exposure to plasma causes a decrease in the fibrinolytic activity of both bound tPA and enzyme released from the surface of the polymer. These data demonstrate that surfactant-treated prostheses can bind tPA, and that these chemically modified devices can act as a slow-release drug delivery system with the potential for reducing prosthesis-induced thromboembolism.

ROLE OF rhBMP-2 AND rhBMP-7 IN THE METABOLISM AND DIFFERENTIATION OF OSTEOBLAST-LIKE CELLS CULTURED ON CHEMICALLY MODIFIED TITANIUM SURFACES

2012 ◽  
pp. 141208072802005
Author(s):  
Fabiano Ribeiro Cirano ◽  
ADRIANE TOGASHI ◽  
MARCIA MARQUES ◽  
FRANCISCO PUSTIGLIONI ◽  
LUIZ LIMA
Keyword(s):  
Chemically Modified ◽  
Titanium Surfaces ◽  
Cells Cultured

AFM and SEM Characterization of Chemically Modified Electrodes Based on 5-[(azulen-1-yl) methylene]-2-thioxothiazolidin-4-one

2018 ◽  
Vol 68 (12) ◽  
pp. 2799-2803
Author(s):  
Maria Daniela Pop ◽  
Oana Brincoveanu ◽  
Mihaela Cristea ◽  
George Octavian Buica ◽  
Marius Enachescu ◽  
...  
Keyword(s):  
Glassy Carbon ◽  
Roughness Parameter ◽  
Modified Electrodes ◽  
Chemically Modified Electrodes ◽  
Adhesion Properties ◽  
Chemically Modified ◽  
Controlled Potential ◽  
Constant Potential ◽  
Metal Ions Detection

Preparation and microscopy characterization of polymer modified glassy carbon electrodes based on (5-[(azulen-1-yl) methylene]-2-thioxothiazolidin-4-one (L) were reported. Atomic Force Microscopy was used to investigate the morphological and mechanical properties of the deposited polyL films onto glassy carbon. The topography images of the analyzed samples exhibited the presence of some columnar shape features onto the layer surfaces. The surface roughness of the layers deposited at constant charge calculated from topography images, increased with the more positive applied potential for controlled potential electrolysis. At different charges, the roughness parameter showed the same behavior for the layers obtained applying a constant potential without having a noticeable influence on the adhesion properties on the substrate. Analysis using scanning electron microscopy shows a relatively uniform surface arrangement of the polymer and the presence of some clusters which are disturbing the planarity. PolyL chemically modified electrodes have been used for heavy metal ions detection with best results for lead.

Synthesis and Structural Studies of Bismuth-piroxicam Complex

2018 ◽  
Vol 69 (7) ◽  
pp. 1702-1705
Author(s):  
Ayesha Kanwal ◽  
Muhammad Imran ◽  
Zafar Iqbal ◽  
Summia Rehman ◽  
Zeeshan Danish ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Bismuth Nitrate ◽  
Stoichiometric Ratio ◽  
Structural Studies ◽  
Ambient Conditions ◽  
Analgesic Drug ◽  
Photoluminescent Property ◽  
Chemically Modified ◽  
Bismuth Complex ◽  
Luminescent Behavior

Piroxicam [4-hydroxy-2-methyl-N-2-(pyridyl)-2H-1,2-benzothiazine-3-carboxamide 1,1-dioxide] is an effective antiinflammatory analgesic drug. In the present work, piroxicam has been chemically modified into its bismuth complex by reacting it with bismuth nitrate at ambient conditions and optimized stoichiometric ratio. The synthesis of the complex has been monitored by TLC and characterized well by Fourier Transform Infrared (FTIR), UV-Vis, ICP, TGA, XRD and SEM. The luminescent behavior of this complex has also been studied which determined its photoluminescent property.

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